Internal combustion engines having fuel injectors typically incorporate a throttle body for controlling the air flow into the engine. By controlling the amount of air flow through the throttle body, the fuel-to-air mixture can be adjusted, and thus, the running performance of the engine can be controlled. Typically, a throttle body allows a relatively low flow rate of air to pass therethrough when the engine is idling, and allows an increased flow rate of air to pass therethrough during wide open or full throttle engine operation.
It is known to incorporate a “butterfly” type valve within a throat of a throttle body to control the amount of air flow therethrough. Generally, the butterfly valve pivots or rotates with a shaft between an idle position substantially restricting air flow through the throttle body and a wide open position permitting increased air flow through the throttle body. Even when the butterfly valve is in the wide open position, the valve occupies at least a portion of the air passage or throat of the throttle body. As a result, the valve provides some restriction to air flow through the air passage or throat at all times.
It is also known to have a sensor communicating with a throttle body to detect the position of the butterfly valve within the throttle body. The sensor typically communicates with an engine control unit (ECU) so that the ECU can determine and control adjustments within the engine to optimize the running performance of the engine. Typically, the sensor is an intricate rotary style sensor that is unique in design for the given application. As a result, both in manufacture and in service, the sensors are relatively costly.